Spark Plug Conversion and Cross Reference Chart: Understand Which Plugs to Use

January 27, 2012

A spark plug conversion chart makes it very easy to ensure that the spark plugs you purchase are compatible with your vehicle. It is important that certain specifications of the spark plugs are the same, otherwise the car will not run properly. The charts all compare the technical spark plug information and show which spark plugs can be used in place of your old spark plugs. Even if sparkplug upgrades are being used, certain specifications still need to be the same.


The spark plug seals the combustion chamber and will conduct a spark that is used for ignition. It also conducts heat from the cylinder head to the cooling system. There are 3 different components of the spark plug; electrodes, insulator and the shell. The shell is actually a metal that uses a threaded hex design and seals the combustion chamber. It is also used to install and remove the spark plug. There are ISO and SAE standards for the thread pitch, thread diameter and hex size. There are 2 threads, a tapered type and surface that is flat machined. These types of threads cannot be interchanged. The insulator is used to ensure that the plug does not ground anywhere, but the gap found in the combustion chamber. It also moves heat to the cooling system. Insulators can be made of many different materials. The electrodes conduct the spark into the combustion chamber. Again this component can be made of several different materials.

Which Plug?

For the best performance, it is always recommended that you use the spark plug found in the manufacturers specs. Many times a different spark plug can be used in an emergency, but be sure to replace this temporary one with the correct one as soon as possible. Using the correct spark plug is necessary because of the heat range of the different plugs. A plug with the wrong threads will not thread into the cylinder head. A resistor plug should never be used in place of a nonresistor plug, and if the reach is too long, then the bottom of the plug and the top of the piston can collide and cause damage. There are also cold spark plugs and hot spark plugs. Cold spark plugs will have tips that function at cooler temperatures. The cross reference charts will show which spark plugs all have the same features so they will fit in the cylinders properly and not cause any ignition problems.


Different materials are used in different components of the spark plugs to provide better performance and provide a longer life. Platinum, gold and copper are all used to dissipate heat quickly. Platinum tipped and platinum electrodes provide some of the longest lasting spark plugs. A gold electrode can greatly reduce the wear of this component. Ensure that the different material spark plug meets all the specifications for your engine. Just because it offers better performance does not mean it will do a lot. Many times, upgrading to an ultra premium spark plug for a small engine does not actually affect the performance. The different materials cannot produce any heat or energy but they are great conductors. The energy and heat is produced from the engine.

Related Questions and Answers

What Happens to the Combustion Chamber when the Engine Floods?

When the engine combustion chamber floods, today's cars are mostly fuel-injected. So you not only have a no-start problem, like the carburetor days, but since each injector is run by its own set of electronics. It might indicate that the electronics for that injector have gone. It also may be squirting more fuel than is needed, directly into the cylinder. The first thing to do is have some patience. Eventually the fuel will drain out of the cylinder or it will become aromatic enough so that it will spark and ignite. When this happens, you will feel the car running rough for a few minutes and probably putting out lots of black smoke. At this point, take the care to a service shop and have the cylinder checked. The chances are good the electronics that control the amount of gas to the cylinder have gone awry. Have your mechanic fix this quickly, as this is a situation that can lead to contaminated oil and other engine damage.

What Tools do You Need to Fix a Spark Plug?

Spark plug tools are easy to define. Indeed, unless the plug has been cross-threaded by an earlier mechanic, all you need is a ratchet wrench, extension, and the spark plug heat - the one with the grommets inside. Simply and carefully remove the terminal wire from the spark plug, lay it aside, and then using even pressure, remove the spark plug. Never force the plug because you could break the ceramic and that will lead to all kinds of problems. Once the spark plug is out, use a gapping tool. It's a little fanlike tool with small wires on the end. Gently tap the electrode until there's tension on the gapping tool. Then reverse the process. You'll likely need pliers to remove the terminal wire.

Privacy Policy|Terms of Use|Cookie Policy|Disclaimer
COPYRIGHT 1999-2019 MH Sub I, LLC dba